World Wide Web

Hal Berghel and Yonina Cooper Dept. of Computer Science
University of Nevada at Las Vegas

The World Wide Web (Web) is a "finite but unbounded" collection of media rich digital resources which are connected through high-speed digital networks. It relies upon an Internet protocol suite which supports cross-platform transmission and rendering of a wide variety of media types (i.e. multimedia). The cross-platform delivery environment represents an important departure from more traditional network communications protocols like email, telnet and FTP because it is content-centric. It is also to be distinguished from earlier document acquisition systems such as Gopher and WAIS (Wide Area Information Systems) which accommodated a narrower range of media formats and failed to include hyperlinks within their navigation protocols. Following Gopher, the Web quickly extended and enriched the metaphor of integrated browsing and navigation. This made it possible to navigate and peruse a wide variety of media types effortlessly on the Web, which in turn led to the Web's hegemony as an Internet protocol.

While earlier network protocols were special purpose in terms of both function and media formats, the Web is highly versatile. It became the first convenient form of digital communication which had sufficient rendering and browsing utilities to allow any person or group with network access to share media-rich information with their peers. It also became the standard for hyper-linking cybermedia (cyberspace multimedia), connecting concept to source in manifold directions identified primarily by Uniform Resource Locators (URLs).

In a formal sense, the Web is a client-server model for packet-switched networked computer systems defined by the protocol pair Hypertext Transfer Protocol (HTTP) and Hypertext Markup Language (HTML). HTTP is the primary transport protocol of the Web, while HTML defines the organization and structure of the Web documents to be exchanged.

HTTP and HTML are higher-order Internet protocols specifically created for the Web. In addition, the Web must also utilize the lower-level Internet protocols, Internet Protocol (IP) and Transmission Control Protocol (TCP). The basic Internet protocol suite is thus designated TCP/IP. IP determines how datagrams will be exchanged via packet-switched networks while TCP builds upon IP by adding control and reliability checking.

The Web can be thought of as an extension of the digital computer network technology which began in the 1960s. Localized, platform dependent, low-performance networks became prevalent in the 1970s. These local area networks (LANs) were largely independent of, and incompatible with, each other. In a quest for technology which could integrate these LANs, the US Department of Defense, through its Advanced Research Projects Agency (ARPA) funded research in inter-networking (i.e. inter-connecting LANs via a wide area network (WAN) ) which resulted in the first national network, ARPANET. For most of the 1970s and 1980s ARPANET served as the primary network backbone for interconnecting LANs for both the research community and the US Government. The open architecture and being built upon a robust, highly versatile and enormously popular protocol suite, TCP/IP, resulted in rapid growth and the gradual evolution into the Internet.

The Web was conceived by Tim Berners-Lee and his colleagues at CERN (now called European Laboratory for Particle Physics) in 1989 as a shared information space which could support collaborative work. Berners-Lee define HTTP and HTML at that time and as a proof-of-concept prototype developed the first Web client navigator-browser in 1990 for the NeXTStep platform. Nicola Pellow developed the first cross-platform Web browser in 1991 while Berners-Lee and Bernd Pollerman developed the first server application - a phone book database.

Despite the original design goal of supporting collaborative work, Web use has become highly variegated. The Web has extended into a wide range of products and services offered by individuals and organizations, for commerce, education, entertainment, "edutainment", and even propaganda. Most Web resources are still set up for non-interactive multimedia downloads with the dominant Web theme being static HTML documents and non-interactive animations.

Yet Web technologies have evolved beyond the original concept. The support of the Common Gateway Interface (CGI) within HTTP in 1993 added interactive computing capability to the Web. An important use of CGI has been the processing of CGI forms which enable input from the Web user-client to be passed to the server for processing. Forms were added to HTML around 1994 and allowed users to give feedback through standard GUI objects (e.g. text boxes, check boxes, buttons). Another technological advance began in 1994 with "helper apps:" extensions of the network browser metaphor which diminished the browser-centricity by supporting multimedia through separate, special-purpose "players. In this way, a wider range of multimedia could be rendered than could be economically and practically built into the browser itself. Web browsers now include generic launchpads which could spawn pre-specified multimedia players based on the filetype/file extent. This generic, browser-independent approach would be challenged twice in 1996, first by "plug-ins" and then by "executable content." Plug-ins, as the name implies, are external applications which extend the browser's built-in capability for rendering multimedia files. Unlike helper apps which rendered the multimedia in an external window, plug-ins render the media within the browser's window in the case of video, or with simultaneous presentation in the case of audio. In this way the functionality of the plug-in is seamlessly integrated with the operation of the browser and as a result often proprietary and browser-specific because of this tight integration. While plug-ins proved to be a useful notion for creating extendable browsers, plug-in developers had to write and compile code for each target platform. This was eliminated through the notion of executable content which maintained the tight integration between the multimedia peruser and browser. The enabled browser will download the executable files which render the multimedia and execute them as well, all within the browser's own workspace on the client. This added a high level of animated media rendering and interactive content on the client side. There are several competing paradigms for Web-oriented executable content (e.g. scripting languages). However, executing foreign programs downloaded across the networks is not without security risk.

Several methods for dynamically creating webpage content have evolved, e.g. Dynamic HTML (DHTML) and Server-Side Includes (SSI). . Both server-push and client-pull technologies provide data downloads without user intervention. (Server-push has been used to produce multiple-cell animations, slide shows, "ticker tapes", automatic pass-through of splash pages, etc.) A multitude of media-rich (if not content-rich) channels are available for use with this technology.

The World Wide Web represents the closest technology to the ideal of a completely distributed network environment for multiform communication. Perhaps the most significant impact of the Web will occur when it becomes a fully interactive, participatory, and immersive medium by default. Security and priivacy issues will continue to emerge as new methods are integrated into current Web technologies. The Secure Socket Layer is a security protocol that sits on top of TCP/IP to prevent eavesdropping, tampering or message forgery over the Internet. Secure HTTP is a secure protocol over HTTP for identification when entering a server. Yet it currently takes extra effort for Web users and servers to insure secure communication so needed by commonplace commerce. Although "cookies" were introduced to make the Web experience more useful by recording information about individual network transactions, they allow tracking of a user which is seen by many as a loss of privacy.

The world will continue to become a smaller place as cultures continue to be only a click away. The Web promises to have one of the largest impacts on general society of any technology thus far created.